Lithiophilic Sb surface modified Cu nanowires grown on Cu foam: a synergistic 1D@3D hierarchical structure for stable lithium metal anodes

Abstract

The uncontrollable lithium (Li) dendrite growth during repeated cycles is a safety risk and is an undesirable electrochemical property of Li metal batteries (LMBs) that hinders the commercialization of LMBs. To realize a dendrite-free Li anode, a hierarchical lithiophilic current collector was fabricated with Sb modified Cu nanowires on Cu foam (1D@3D-Cu/Sb). The 3D porous Cu foam scaffolds have ample space which can buffer the volume changes and provide a reduced local current density. Moreover, the Sb modified 1D Cu nanowires with a secondary structure of an homogenized Li⁺ flux provide numerous lithiophilic sites for uniform Li⁺ deposition, further suppressing the Li dendrite formation. Consequently, the 1D@3D-Cu/Sb as a Li host operates for over 900 h with a low overpotential (∼11 mV) without intense voltage fluctuation for symmetrical cells. Furthermore, the full cells pairing Li-deposited 1D@3D-Cu/Sb with a LiFePO₄ (LFP) cathode achieves promising cycling stability for 200 cycles at 0.5C.